I did some poking around the internet and found a very long (and dull) document about headrest function and design written by NHTSA.

It is critically important for preventing neck hyperextension in a crash and could be the difference between a spinal cord injury and just normal whiplash. It’s part of the restraint system and anyone who is using a backless booster or a seatbelt alone, absolutely should have a headrest. Let’s look first at the major function of a headrest. I’m going to break this down into two parts: the headrest and the window. MYTH: A vehicle headrest is left deliberately detachable and sharp so that it can be used to break a vehicle’s window and the glass of a vehicle window is easily broken from the inside. Is this true? Because if so, I had no idea and what a great hidden trick! If not, then it is probably sort of dangerous for people to be spreading it to others when there are devices that are specifically created to help break windows in an emergency. For some reason, this myth has become wildly popular and everyone seems to be very excited about the implications and benefits of this information. Every once in a while, a meme goes around on social media that catches my attention.

Crash And Smash Cars for windows instal